Missouri Basin River Forecast Center
Water Supply Statement
Issued in cooperation with the Natural
Resources Conservation Service
Issued:  August 10, 2007

Precipitation in the Missouri Basin was highly variable during July.
Most of the Montana received below average rain while Colorado and
Wyoming reported average to above average rainfall. Streamflow data
indicates the flows for July were below average.

Precipitation in Montana below average with amounts ranging from a trace
or less at Augusta, Cut Bank 34NW, and Sweetgrass, Montana; to 277
percent of  average (4.74 in.) Rapelje, Montana. Precipitation in
Wyoming was average to above average. Reports ranged from 19 percent of
average (0.19 in.) at Powell 23NW, Wyoming to 189 percent of average
(3.18 in.) at Riverton 1SW, Wyoming.  Precipitation in northeastern
Colorado was average, with reports ranging from 36 percent of average
(1.01 in.) at Burlington 4S  to 192  percent of average (4.40 in.) at
Lake George 8SW, Colorado.

Basin precipitation summaries for the Missouri Basin:

Basin               Average Precipitation
Milk St. Mary                15%
Milk Canada                   7%
Above Toston                61%
Toston to Ft. Peck         43%
Lower Milk                     43%
Upper Yellowstone        82%
Wind River                   166%
Bighorn                         101%
Little Bighorn Tongue    67%
Powder                         107%
Lower Yellowstone         52%
Upper North Platte       100%
Lower North Platte         96%
North Platte Plains         86%
South Platte Mountains  103%
South Platte Plains        110%


 

July 2007 Basin Mean Precipitation


Stored water in the South Platte Basin as of August 1 was 91
percent of average for this time of the year. Stored water in the
North Platte Basin was 46 percent of average. Stored water in Boysen
Reservoir was 55 percent of the 30 year average. Buffalo Bill
Reservoir held 98 percent of average storage. Of the four
major irrigation reservoirs in Montana, Lima Reservoir had 47 percent
average storage; Clark Canyon was holding 50 percent of average water,
Gibson Reservoir had 19 percent of average stored water and Fresno
Reservoir had 103 percent of average stored water. Of the three major
hydroelectric reservoirs in Montana, Canyon Ferry and Fort Peck had
monthend storage in the average range; 95 and 56 percent of average water,
respectively. Bighorn lake was holding 97 percent of average
stored water.


Runoff during July, as indicated by U.S. Geological Survey longterm gaging stations,
was much below average. The Marias River near
Shelby, Montana had 18 percent of average runoff. The Yellowstone
River was estimated to have had 40 percent of average runoff at
Corwin Springs, while at Billings, Montana runoff was 28 percent of
average.

          Precipitation Maps

 
          July 2007        Oct-July WY 2007

                          

July 2007 Precipitation Percent of 1971-2000 Average  Oct-Jul  WY2007 Precipitation as Percent of 1971-2000 Average


July 2007 Basin Mean Precipitation                    Oct-Jul WY2007 Basin Mean Precipitation

                               

July 2007 MBRFC Basin Mean Precipitation              Oct-Jul WY2007 MBRFC Basin Mean Precipitation

 


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